I say play Cora until like Crespo said earlier he cools off. When you have a hot bat you ride it. I am not sold that Pedroia is ever going to be that good, but I suppose you have to give him a chance to play a little more. If he doesn't respond at all this season then they better be looking for another fix at 2nd base this offseason.
For the time being I really do like Cora at second though. He is an above average defender and he can handle the bat very well. Sure he may not hit .300, but if he gets consistent playing time, he could probably hit around .270, maybe hit 8-10 homeruns and drive in 50-60 runs. He improves the infield defense, and he is a solid situational hitter IMO. Right now with a runner at 3rd with less than two outs, I feel most confident that other than Ortiz right now, Cora is the guy I want at the plate. He just knows how to play and help the team win ballgames.